Molecular characterization of fossil organic matter in Glyptostrobus europaeus remains from the Orawa basin (Poland). Comparison of pyrolytic techniques

Pyrolytic methods (standard Curie-point pyrolysis and pyrolysis in the pres ence of tetramethylammonium hydroxide (TMAH), followed by gas chromatograph y-mass spectrometry, were used to analyze the organic composition of Glypto strobus (Taxodiaceae) remains from the Miocene deposits of Lipnica Mala (Po land), consisting of branches with their leaves. The pyrolytic analysis rev ealed a series of aromatic compounds with a large proportion of guaiacyl-ty pe lignin markers (including intact C-3-methoxyphenols), and small quantiti es of polycyclic aromatic hydrocarbons. The alkyl compounds included fatty acid series where the C-14-C-18 homologues dominated as well as additional amounts of alkanes and alkenes (maximum ca. C-21). The results suggest that lignin as well as protective epicuticular lipid polymers (including cutin and other long chain-based polyalkyl structures) selectively show the great est degree of molecular preservation in the Glyptostrobus remains. The comp arison between pyrolytic methods shows that the lignin-derived aromatic ass emblages predominate in the chromatograms after conventional pyrolysis wher eas thermochemolysis with TMAH leads to an "aliphatic enhancement". This la tter technique was found to be the best for analysis of the lipid signature in fossil samples with condensed polymethylene networks. (C) 1999 Elsevier Science Ltd. All rights reserved.